A novel red light emissive two-photon fluorescent probe for hydrogen sulfide (H2S) in nucleolus region and its application for H2S detection in zebrafish and live mice

Hydrogen sulfide (H2S) has been recognized as one of the most important gaseous signaling molecules and it is extensively present in cells. Detection of H2S in biological samples by fluorescent imaging techniques is advantageous due to the real-time, noninvasive nature of these techniques. However, owing to the protective obstacle of the cell nucleus membrane, it is hard for a fluorescent probe to detect H2S near the nucleolus region. Herein, we report the first example of a novel two-photon fluorescent probe 1-H2S for H2S with red light emission that can detect H2S near the nucleolus region. The probe was constructed through extending the conjugated system of naphthalene and coumarin analogue. 1-H2S showed obvious fluorescence enhancement in the presence of 50 equivalents Na2S (PBS, pH 7.4 buffer) and high selectively toward H2S in solution. In biological experiments, the fluorescent probe was found to aggregate in the nucleolus region of cells and can detect H2S near the nucleolus region. The probe was also applied for fluorescence imaging of H2S in zebrafish and live mice model successfully. (C) 2017 Elsevier B.V. All rights reserved.